1. Field of the Invention
The present invention relates generally to graphical object positioning on electronic displays, and more particularly to a system for integrating coarse and fine graphical object positioning on an electronic display.
2. Description of the Related Art
Electronic flight display systems, which provide a means for the pilot to manually position graphical objects, can be labor intensive and cause high workload to use in cases where positioning the object at the desired display location has to be relatively accurate. Existing designs use one of two types of positional control devices (i.e. elements) to accomplish this task.
Some of these designs use control devices such as a joystick, trackball or touchpad which provide for rapid movement of the graphical object. This allows for coarse but quick traversal of the graphical object over long lengths on the display. However, these designs are highly inefficient for fine placement on the display since priority is given to rapid movement rather than positional accuracy. The time gained by the quick traversal is lost when trying to position the graphical object by small amounts to reach the desired location on the display. This situation can be compromised even further when performing this task during turbulent flight conditions.
Other existing designs use a different type of control device such as a rotary knob or scroll wheel with detents that provides for small uniform incremental movements of the graphical object. This allows for fine placement of the graphical object over short lengths on the display. However, these designs are highly inefficient for coarse but quick traversal over long lengths on the display since priority is given to positional accuracy rather than rapid movement. The time gained by accurately positioning the graphical object by small amounts is lost when a long length needs to be traversed to reach the desired location on the display. Like the prior control devices described above, this situation can be compromised even further when performing this task during turbulent flight conditions.
U.S. Pat. No. 6,795,055, issued to J. H. Culler, entitled “Devices, Systems and Methods for Facilitating Positioning of Cursor On Display Device,” discloses an input device which includes a shifter configured to electrically communicate with a computer. The shifter is configured to enable functional information, provided by a mouse-type input device, to provide selected functionality of the cursor. The shifter provides a shift-disable mode and a shift-enable mode so that, while in the shift-disable mode, the shifter enables the mouse-type input device to influence movement of the cursor on the display device. For instance, a movement of the mouse-type input device in a first direction and a first distance results in the cursor moving the first direction and a corresponding second distance. In the shift-enable mode, the shifter enables an altering of movement of the cursor so that movement of the mouse-type input device in the first direction and the first distance results in the cursor moving the first direction and a corresponding third distance, with the third distance being unequal to the second distance. This device is also disclosed in U.S. Pat. No. 6,545,666, of the same applicant. Both of the above-mentioned patents involve utilizing one device that operates in different modes. The device has two fixed gains. In the shift-disable mode the normal gain typical of a mouse is utilized to translate device motion to on screen cursor motion. In the shift-enable mode, the gains are changed enabling fine positioning. That is, in shift-enable mode, the gains are decreased resulting in larger device motion for smaller on screen cursor motion, thereby enabling fine positioning of the on screen cursor.
U.S. Pat. No. 6,181,325, issued to K. Lee, entitled “Computer System with Precise Control of the Mouse Pointer,” discloses a portable computer system that enables locating the mouse pointer precisely on the monitor screen. The computer system includes a pointing device such as a touch pad mounted at top surface of the main body with two mouse buttons. A button is provided at left sides of the touch pad. This button is similar to the mouse button and used when fine adjustment of the mouse pointer is needed. The operation of the fine adjustment mode performed in the computer is as follows: determining whether a fine adjustment mode selection key is pressed; zooming in a predetermined screen area including current location of the pointer based on the corresponding video driver and operating system; locating the pointer at the desired position within the zoom in screen; checking if the fine adjustment mode has canceled; and restoring the zoom in screen to original picture if the fine adjustment mode is canceled. The cancellation of the fine adjustment mode is performed by detecting the signal fed from one of the mouse buttons. To enable fine positioning of the cursor, the magnification of the on screen display area is increased with the gain of the device being held constant. This has the effect of decreasing the gain of the device, thereby enabling fine on screen cursor positioning.